In order to properly maintain your swimming pool filtration system it is important to periodically change the sand in your pool filter. The sand becomes so saturated with organic debris, skin, hair and oils that it is no longer able to filter the water sufficiently to maintain clarity.

Steps

1

The logic behind never changing your filter sand is that dirty sand actually filters better than brand new sand. The flip side to this is that after enough time the sand will no longer be able to filter the water well enough. From a manufacturer standpoint it is recommended that you change the sand in your filter every 3-4 years. This will maximize the effectiveness of the filter and help you to maintain clean and clear water.

2

Removing the sand with a shop vacuum will be much easier than scooping the sand out by hand or with a small shovel. The sand in an old filter can actually be laden with bacteria so it would be better if you minimize your direct contact with the sand.

3

After removing the old sand you will want to add water to the tank before adding new filter sand. This water helps to absorb any impact of the falling sand on the lateral assembly. Many professional installers skip this step but that would not be recommended if this is your first filter sand change.

4

The type of sand that you add to the filter will be #20 silica sand which is specifically produced for filter media. This sand is between 40-50mm in diameter and is available from most swimming pool supply stores. Do not substitute other types of sand or you will almost certainly have problems with your filter and potentially damage the pool also.

5

The amount of sand that you add to the filter will depend on the size of filter that you have. You must be certain to find accurate information about how much sand to use in your filter. Over filling or underselling the filter will at least cause the filter to not function properly, and at worst cause damage to the filter. Filter sand sizes range typically from 100 or 150 lbs all the way up to 600lbs or more for large pools.

6

Be sure not to get any sand into the sandpipe which will be wide open. It is difficult to get the sand actually into the filter without getting it in the sandpipe so you may like to tape up the standpipe opening to prevent this spilled sand from making it back to the pool through the return lines. It is also very important that the sandpipe is directly in the center of the filter as once you have filled with sand you will not be able to adjust the position of the sandpipe. If not centered you will not be able to get the valve head back on the filter and will need to start all over again.

7

Once full you can put the filter head back on being absolutely certain that it is tight enough. This is where a skilled hand is helpful as if you overtighten the filter head then you may actually crack the filter body which would require replacement of the entire filter tank - something you definitely want to avoid.

8

Once back together the first thing you need to do is give the filter a thorough backwash. You should start this process by over filling the pool and then backwashing for as much as 3 to 5 minutes, followed by a 60 second rinse cycle before setting to "filter".

Community Q&A

I changed the sand filter per the instructions. The hoses are hooked up correctly. But when I clean the pool, everything I clean comes back out the exhaust. What can I do?

wikiHow Contributor

Back out the exhaust? If you mean that it discharges to sewer, then the problem is probably the spider gasket in the multi-port valve. One of spokes has failed. If you mean the vacuum just blows right back into the pool through the return inlets, then make sure you have the multi-port valve on "filter" not "recirculate" or "bypass". After backwashing, you should "rinse" for a minute or so. Never turn multi-port valve handle with the pump running. If none of this helps, then you probably have to reopen the filter. Either the water has blasted channels through the sand so that water travels through the filter without actually going through sand or the lateral or standpipe knocked loose when you added new sand.

The filter will fill up once connected to the pump. Here in the northeast, we have to winterize the filter and drain all of the water out. In the spring, close the drain plug and turn the filter on and it fills it up and eventually all of the trapped air is removed via the tube.

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Video

Warnings

It is normal to have some sand back into the pool or out through the waste line when you change your filter sand as some of the sand that you received will be smaller than #20 and this smaller sand will eventually work its way out of the filter. The long initial backwash that you do when you change the sand will help to minimize this.

"I was concerned about whether to change the sand in my pool filter and how often it should be done. This article not only explained that in detail, but showed me in detail how to do it, too. In fact, I feel comfortable doing it myself. Thank you."..." more

SS

Sherry Sullivan

Jun 16, 2016

"The information was very helpful. Last time I changed my filter sand, I got a lot back into the pool when I started filtering. Now I see why. I did not backwash the sand before starting to filter. Thanks for the advice."..." more

LS

Leslie Safar

Jun 15

"It made it clear to me what has to be done, why and how. It is an excellent article."

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Melissa Burke

Jul 5, 2016

"I own an in-ground pool for the 1st time and would be lost without wikiHow.com! "